rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=512c/1/0x4000000000000000 softirq=82960/82963 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6020/1:b..l rcu: (detected by 0, t=10502 jiffies, g=70605, q=231 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11256 Comm: syz-executor Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:advance_sched+0x4ea/0xc90 net/sched/sch_taprio.c:-1 Code: 89 44 24 08 48 8b 03 49 39 c7 49 0f 4c c7 48 89 44 24 20 0f b7 f5 31 ff e8 23 d4 39 f8 66 85 ed 0f 8e 31 02 00 00 48 8b 04 24 <48> 05 30 01 00 00 4d 8d 6e 80 48 ff cd 45 31 ff 48 89 44 24 50 48 RSP: 0018:ffffc90000a08c70 EFLAGS: 00000002 RAX: ffff88805a192800 RBX: ffff88805a192928 RCX: 0000000000010000 RDX: ffff8880679b3c00 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: dffffc0000000000 R13: ffff88807dfc8000 R14: ffff88805a193140 R15: 1867a9e531ea77c6 FS: 00005555754f7500(0000) GS:ffff888125d57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000009000 CR3: 000000005c0fa000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0xe/0x2390 arch/x86/kernel/unwind_orc.c:469 Code: 48 89 df e8 a4 62 ad 00 eb 88 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 <48> 81 ec 98 00 00 00 49 89 fe 48 bd 00 00 00 00 00 fc ff df 48 8d RSP: 0018:ffffc90010707670 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90010707760 RCX: 8f81311b840db900 RDX: dffffc0000000000 RSI: ffffffff8b6630da RDI: ffffc900107076a8 RBP: ffffc90010707730 R08: ffffc90010707770 R09: 000000000000000a R10: ffffc900107076f8 R11: ffffffff81acfd40 R12: ffff8880679b3c00 R13: 1ffff920020e0f58 R14: ffffffff81acfd40 R15: ffffc900107076a8 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3094 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3214 __destroy_inode+0x2da/0x670 fs/inode.c:371 destroy_inode fs/inode.c:394 [inline] evict+0x797/0x9c0 fs/inode.c:834 __dentry_kill+0x209/0x660 fs/dcache.c:669 dput+0x19f/0x2b0 fs/dcache.c:911 __fput+0x68e/0xa70 fs/file_table.c:473 fput_close_sync+0x119/0x200 fs/file_table.c:570 __do_sys_close fs/open.c:1589 [inline] __se_sys_close fs/open.c:1574 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1574 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f66af78d84a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 43 91 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 a3 91 02 00 8b 44 24 RSP: 002b:00007fff52f0a0a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f66af78d84a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fff52f0a0fc R08: 00007fff52f099ec R09: 0079746972756365 R10: 00007fff52f09a50 R11: 0000000000000293 R12: 00000000000000a9 R13: 00000000000927c0 R14: 00000000000cb712 R15: 00007fff52f0a150 task:kworker/u8:9 state:R running task stack:21152 pid:6020 tgid:6020 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 6b 55 fe 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000560f980 EFLAGS: 00000206 RAX: d9891f8d864ed500 RBX: 0000000000000000 RCX: d9891f8d864ed500 RDX: 0000000000000000 RSI: ffffffff8db6fcc6 RDI: ffffffff8be1ba40 RBP: ffffffff8b345592 R08: 0000000000000000 R09: ffffffff8b345592 R10: dffffc0000000000 R11: ffffffff8b3454c0 R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: rcu_preempt kthread starved for 10498 jiffies! g70605 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16aa/0x4c90 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 14337 Comm: syz.4.2199 Not tainted 6.16.0-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 80 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 2b 6a 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 10 6a 0b RSP: 0018:ffffc900014275a0 EFLAGS: 00000293 RAX: ffffffff81b4bbb0 RBX: ffff8880b863b040 RCX: ffff88801e359e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90001427700 R08: ffffffff8fa0b3f7 R09: 1ffffffff1f4167e R10: dffffc0000000000 R11: fffffbfff1f4167f R12: 1ffff110170e7f2d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873f968 FS: 0000000000000000(0000) GS:ffff888125c57000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc8882dfa8 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x17c/0xb50 mm/mmap.c:1270 __mmput+0x118/0x410 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x648/0x22e0 kernel/exit.c:952 do_group_exit+0x21c/0x2d0 kernel/exit.c:1105 __do_sys_exit_group kernel/exit.c:1116 [inline] __se_sys_exit_group kernel/exit.c:1114 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1114 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc66b38ebe9 Code: Unable to access opcode bytes at 0x7fc66b38ebbf. RSP: 002b:00007ffc88830708 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007fc66b4128b7 RCX: 00007fc66b38ebe9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 000000000000000c R08: 00007ffc8882e4a6 R09: 00007ffc88830830 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc88830830 R13: 00007fc66b25ece0 R14: 00007ffc88830828 R15: 0000000000000003